100 to 120 is the physiological level.
To reduce autoimmune attack the level has to be higher, around 200nmol/L. This is what is sued for MS - read the Wahls Protocol chapter on supplements.
I’d except Sjogren to be similar. The reson is the immune cells can take on two forms: in autoimmune attack mode ( Th1 and M1 form) or asupprotive benficial mode(Th2 and M2). D3 will switch mode 1 to mode 2.
But these cells make their won 1,25OHD3 starting with D3. They do not use ciculating 25OHD3. Now, in attack mode1 the cells switch off their own synthesis of 1,25OHD3 and become lokced onmode 1. Until a really high blood levle of D breaks through the switch. If you want to read further in M1 mode NFkappaB is produced in the cells and this kills D3 hydroxylation…
I take 10,000IU per day for PD. It is an experiment that I expect to work. The only trial, in Japan, used 1200IU D3, a miserbale dose, for only three months. I also take mitochodrial suporting agents, all endogenous bichemicals. Same as in the Wahls Protocol. I raised the D3 does slowly, first 2000IU for three months then measured serum (turned out at 100nmol/L), then 6000IU for three months ( serum 170nmol/L), now on 10,000 , one month to go to measuring. My psoriasis, an autoimmune skin condition, became less aggressive as serum level was rising towards 170nmol/l…so 2000IU did not change it, 6000 did.
Hope this helps,